Have the kids create crafty sea creatures. Start by showing them illustrated children's books such as Kevin Sherry's "I'm the Best Artist in the Ocean." Discuss what the various creatures look like in terms of shapes, colors and patterns. Use a paper bag to craft a fish puppet, adding construction paper fins and a tail with glue or add eight pieces of yarn to the body of the bag to make an octopus. Design dramatic fish drawings and paintings with an added sparkle of glitter or make cut round or oval shapes for the children to decorate as fish or octopi.
Explore the undersea world of aquariums. Read aloud books on undersea life and talk about survival in the underwater environment. For an overall aquatic experience take the preschoolers on a trip to a local aquarium; book an educational tour or simply encourage the kids to view various sea life. In the classroom, stock a tank with colorful fish, pebbles and real plants. Kids can observe and perform some of the maintenance tasks such as feeding the fish. Have the preschoolers document the underwater habitat by writing a few simple words in a science journal or drawing a picture of what they see.
Turn the dramatic play center into an undersea adventure with toy fish, fake plants and blue fabric to simulate waves. Discuss what you might find on a beach and in the ocean and invite the children to create their own environment. Have the kids turn cardboard boxes into rolling waves by painting blue streaks on the sides or underwater scenes complete with fish, dolphins and more. Encourage the preschoolers to pretend to be sea creatures swimming through the water or to become rolling waves. Play a CD of underwater sounds or waves sloshing onto the beach. Talk about how various creatures move and how it might feel for them to swim through the ocean.
Explore water science through hands-on experiments. Students can learn about density by pouring a mixture of blue food coloring and vegetable oil together into a clear cup of water. Have them predict what may happen before starting the experiment, make observations during the process and discuss why they think the oil floated. Show the preschoolers differently weighted objects such as rocks, feathers or small plastic toys; ask them to predict which ones will sink or float. Place the objects in a tub of water and observe what happens. Talk about saltwater and freshwater in oceans, rivers and lakes. Add a few tablespoons of salt to see how it effects floatation.